Motor trucks carrying a foldable crane



Feb. 26, 1957 H. F. J. BERNAERTS MOTOR TRUCKS CARRYING A FOLDABLE CRANE File'd Oct. 5, 1954 United States Patent MOTOR TRUCKS CARRYING A FOLDABLE CRANE Henricus F. J. Bernaerts, Weert, Netherlands Application October 5, 1954, Serial No. 460,495 Claims priority, application Netherlands October 13, 1953 2 Claims. (Cl. 212-8) My invention relates to motor trucks carrying a foldable crane and designed particularly, but not exclusively, for handling crashed air craft in areas that are difficult of access, or in hilly or rising ground.

One object of my invention is to provide a motor truck of the character referred to, which comprises a crane boom pivoted on the axis of the rear wheels and adapted to fold down in forward direction, a crane arm being pivoted to said boom, on an axis in parallel relation with the axis of the rear wheels and intermediate the ends of said boom, so as to be adapted to fold down in rearward direction.

Another object of my invention is a motor truck of the character referred to, which comprises, in addition to means for varying the gauge of the rear wheels, a jack for lifting the rear wheels from the ground. As far as I am aware, such means have never been embodied in motor trucks carrying a crane, although they are known per se in railway cars and agricultural implements.

Further objects of the invention are set forth in the following description, which discloses a preferred embodiment of the motor truck illustrated, by way of example, in a sectional side view by the accompanying drawing.

1 is the front frame or bogie of the truck, said frame being supported by two wheels 2. Mounted in said frame are a combustion engine 3 and transmission mechanism 11 through which said wheels can be individually driven at variable speeds.

The rear frame of the truck is also supported by two wheels 5 and carries a folda'ble crane, which comprises a boom 6 and a crane arm 7 pivoted thereto about centrally between the ends thereof. The boom is adapted to be swung, about the axis of the rear wheels, into vertical position, the crane arm being adapted to be adjusted so as to enclose any desired angle with the boom by means to be described hereinafter.

The front or leading frame and the rear or trailing frame of the truck are interconnected so as to have freedom of rotation relative to one another about a vertical axis. To this end the rear frame comprises a horizontal circular disk 9 supported by a corresponding, coaxial circular disk 10 on the front frame, said disks being relatively rotatable about a vertical axis. Moreover, the disk 10 is pivoted, through horizontal trunnions 33, 34, on a horizontal axis in the longitudinal, vertical central plane of the truck.

Secured to the trailing frame at the rear end thereof is at least one jack 32 for lifting the rear wheels, the gauge, i. e., the spacing, of which can be varied by means not shown.

A hydraulic actuator 12 is hinged to the boom 6 intermediate the ends thereof. The plunger of said actuator is adapted to engage a lateral projection on the crane arm 7 so as to support the latter, guiding means 35 being provided on the said arm to ensure the required engagement.

Hinged to the rear frame 4 is another hydraulic actuator 13, whose plunger is pivoted to the boom 6. The length of stroke of this actuator is such as to allow the boom 6 to be swung, about the axis of the rear wheels, into vertical position, and with a view to the length of stroke required for that purpose said actuator will preferably be of the telescoping type.

The hoisting cable 36 is secured to a pin 19 in the vicinity of the distal end of the crane arm 7 and is passed over the sheaves 15, 16 of a pulley block with hook, and thence, over a guide sheave 17 pivoted on the axis of the crane arm 7 and over a guide sheave 18 pivoted on the axis of the boom 6, to the drum of a hoisting winch 14 mounted on the rear frame 4.

Both ends of the cable 37 for lufiing the ornate arm 7 relative to the boom 6 are secured to a pin 20 on the rear frame 4 close to the front end thereof, whence both parts of said cable are passed over the pulleys of the blocks 21, 22 of a tackle and over pulleys 23, 24 pivoted to the distal ends of the boom 6 and of the crane arm, respectively, to a reversing pulley 25 pivoted to the distal end of the boom. The block 22 is stationary, and the block 2-1 is connected to the plunger of a hydraulic actuator 38.

A third cable, designated by 39, has its ends secured to a pin 26 secured to the boom near the distal end thereof, whence said ends are passed over the pulleys 23, 22, 27, 28 and the pulleys of blocks 29, 30 of a tackle to the reversing pulley 31. The block 30 is connected to the plunger of a hydraulic actuator 40.

With the parts described above assuming the positions shown in the drawing, then, when "an object is to be hoisted, pressure fluid is to be supplied to the hydraulic actuators 12 and 38.

Since the obtuse angle between the plane passing through the axes of pulleys 23 and 17 and the plane passing through the axes of pulleys 17 and 24 has a value of nearly the actuator 38 is not capable to swing the crane arm 7 upward. The actuator 12, however, owing to its engagement with the crane arm 7, begins to raise the latter, whereby the value of said obtuse angle is decreased, the consequence being that the actuator 38 becomes operative so as to swing the crane arm further upward by means of the cable 37 and to disengage said arm from the actuator 12. At the end of the outward stroke of the actuator 38, pressure fluid is to be supplied to the actuator 13, owing whereto the boom 6 is swung upward until it reaches its vertical position. The lengths of the cables 37, 39 is such as to ensure that, at this juncture, the crane arm 7 assumes its highest position.

During the upward swinging movement of the boom 6, the cable 39 is payed out, the plunger of the actuator 40 being thereby retracted and the block 30 moved in forward direction. With the boom 6 in vertical position, the crane arm 7 can be angularly adjusted relative to the boom by operating the actuator 38 and thereby moving the block 21 rearward or forward.

By means of the winch 14, the hook of the pulley block 15, 16 can be raised or lowered as circumstances require.

When the crane is to be collapsed or folded down, pressure fluid is to be supplied to the actuator 40 and the pressure fluid in actuators 12, 13 and 38 is allowed to be drained through suitable throttle valves in the discharge conduits thereof, so that the boom and the crane arm return gradually to their initial positions.

It will be understood that the various actuators can be operated, instead of individually, by means of a common control valve.

In many cases it will be advisable, before hoisting a load, to lift the rear wheels 5 from the ground by means of the jacks 32, thereupon to increase the gauge or spacing of said-wheels, and finally to lower the wheels again, thereby increasing the stability of the truck.

What I claim is:

1. A motor truck having from and rear wheels and carrying a foldable crane comprising a frame supported by areas-s9 said front and rear wheels, a boom pivoted on the axis of said rear wheels of the truck and folding down in forward direction toward the front end of said truck in its collapsed inoperative position and a crane arm pivoted to said boom and folding down in rearward direction toward the rear end of said'truck in its collapsed; inoperative position, a first, hydraulically operated actuator disposed between said frame and said boom and adapted to raise said boon! relative to said frame upon the axis of said rear wheels as pivotal axis in to operative posi tion, and a second, hydraulically operated actuator disposed between said boom and said crane arm and adapted to swing said crane arm relative to said boom for 'a first rising run, and cable operated means 'for swinging fnrther said crane arm for second rising run from the position at 4 the end of said first rising run into raised operative position.

2. The motor truck, as set forth in claim 1, in which said crane arm is pivotally connected substantially to the center portion of said boom.

References Cited in the file of this patent UNITED STATES PATENTS 905,208 Mitchell Dec. 1, 1908 1,796,397 R'emde Mar. .17, 1931 1 1 D P ""T.T"'T7TT7"T" W 1952 9351 91 ATE T- 114,610 Anstralia 12111.28, 1942 

